Prevalence of hypokalemia in ED patients with diabetic ketoacidosis

Objective: Although patients with diabetic ketoacidosis (DKA) are expected to have total body potassium depletion, measured levels may be normal or elevated due to extracellular shifts of potassium secondary to acidosis. Because insulin therapy decreases serum potassium levels, which creates potential to precipitate a fatal cardiac arrhythmia in a patient with hypokalemia, the American Diabetes Association (ADA) recommends obtaining a serum potassium level before giving insulin. Although the ADA guidelines are clear, the evidence on which they are based is largely anecdotal. The purpose of this study was to estimate the prevalence of hypokalemia in patients with DKA before initiation of fluid resuscitation and insulin therapy. Methods: This is a prospective cross-sectional descriptive study of patients with a capillary blood glucose level of 250 mg/dL or higher (at risk for DKA) seen in an urban county emergency department over a 1-year period. Those who consented provided basic demographic information and had a venous blood gas and chemistry panel drawn. Diabetic ketoacidosis and hypokalemia were defined using ADA recommendations. Results: The mean age in our sample was 40.2 years, and 81% of patients were Hispanic. Of 503 analyzable patients with hyperglycemia, 54 (10.7%) met all criteria for DKA. Of patients with DKA, 3 (5.6%) of 54 (95% confidence interval, 1.2%-15.4%) had hypokalemia. Two of these patients had values of 3.0 mmol/L, and 1 had a value of 2.8 mmol/L. Conclusion: Hypokalemia was observed in 5.6% of patients with DKA. These findings support the ADA recommendation to obtain a serum potassium before initiating intravenous insulin therapy in a patient with DKA. (C) 2012 Elsevier Inc. All rights reserved.